On Wed, 09 Sep 2009 14:41:14 +0100
Bruce wrote:
On Wed, 9 Sep 2009 12:38:35 +0000 (UTC), wrote:
Really, whys that then? Would the actual boring part of the TBM cost
substantially more if its diameter was increased by a metre? Would the extra
concrete cost raise the project costs much higher? Or are you just BSing
because you always want to appear to know best?
This is an area where I have specialist knowledge, both as someone who
has worked on several tunnelling projects and someone who has been
responsible for tendering for tunnelling projects.
For the record, I don't believe you.
The cost of the tunnelling machine increases quite dramatically with
tunnel diameter; the cost of the excavation and of the tunnel lining
increases approximately with the square of the excavated diameter.
*sigh* I hate to break this pre-GCSE news to you, but the area of the
shaft of a cylinder increases *linearly* with increasing radius, not as the
square of it so the cost of the lining will not go up like that. The formula
you want incidentaly is 2*pi*r*h. So before you post anymore bull****
pretending your in-the-biz you might want to revisit your school books first.
As for the cost of the TBM - an extra metre diamater of the boring plate
would make no difference to the machinary required behind it.
B2003